Foil and film are being used to to ever increasing extents as product packaging materials. These materials include evaporation-inhibiting barrier layers that keep the contents of the package in a completely sealed environment. Packaging intended for products that are not shape-stable in themselves, for instance liquid or powder products, are made of a thicker material, for instance from different types of laminates. These materials provide the packaging with the rigidity required to enable the packaging to be stored, transported and handled and so that the end user of the package will be able to pour-out the packaged contents or to empty the package of its contents. These packaging materials are often relatively heavy in relation to the contents of the packaging container, which is disadvantageous in several respects. Moreover, these packaging containers are not environmentally adapted, since the laminates are comprised of different layers of material that are difficult to recover. The packaging containers also take-up large volumes of space in conjunction with garbage, or refuse, collection.
From an environmental aspect, it is therefore desirable to depart from the use of thick laminates as packaging materials and to use, e.g., foils of smaller thicknesses instead. The use of such thin material thicknesses is counteracted, however, by the requirement of being able to store, transport and handle the packaging containers. When liquids are packed in thin foil bags, it is difficult to handle the bag and its contents per se in a controllable manner. For instance, when lifting such a bag with the intention of emptying the bag of its contents, care must be taken not to squeeze the bag so as to cause its contents to gush uncontrollably through the bag opening.
It is known to produce liquid packaging containers from flexible foil material and to provide the containers with stiffened packaging walls. For instance, it is known from EP A1 0621 208 to produce a packaging container from a flexible material, such as foil, with foil walls that are comprised of double foil layers. The two foil layers are joined together or laminated punctiformly and/or linearly such as to form in the packaging wall a plurality of mutually connected chambers or passageways. The system of chambers or passageways is filled with air or some other gas and sealed, thereby stiffening the wall of the packaging container. A similar foil packaging container for liquids is known from WO 96/01775. This packaging container also includes walls comprised of double foil layers that are mutually joined (laminated) in a manner such that non-laminated, longitudinally extending parts extend from one side of the packaging container to the other. The non-laminated part forms longitudinally extending pockets that are filled with air and then sealed, therewith stiffening the wall of the packaging container.
One serious drawback encountered with the known foil packaging containers is that the packaging walls are not rigid enough to withstand the external pressure that is applied to the packaging container when handling the container and emptying out its contents, or when resealing the container. For instance, it is not possible to grip and lift the packaging container in a normal manner without exerting pressure on the container contents and causing said contents to spill over the opening defining edge of the container. Neither can the packaging container be emptied in a controllable fashion.
Another disadvantage with the known packaging containers is their vulnerability. For instance, the outer foil of the packaging container wall can be readily damaged and therewith cause a lowering of the pressure in the stiffening chambers, wherewith the packaging container completely loses its rigidity. Neither can the known packaging containers be resealed without risk of damaging the packaging walls.
Although the packaging containers are produced from simple and inexpensive materials, such as foils, these packaging containers are nevertheless encumbered with the serious drawback of being complicated and therefore expensive in manufacture.